Subtraction of matrix rows

I like to the subtraction of matrix rows .. EX. A = [ 2 3 4; 3 2 3] ... I want the absolute value from substation the first row from the second row and make the summation of the new row.... so the answer suppose to be as next:... 1. B = [ 1 1 1 ]..... And ..D = 3 ... thank you

Answer 1

[Stephen23]

diff(A)
diff(A,1,1)